On Thursday, White House spokesman Sean Spicer turned to a Fox News analyst's contention British electronic intelligence agency GCHQ had helped Mr Obama wire-tap Mr Trump.
Fox News has said it could not independently verify the reports from Andrew Napolitano, a former judge and commentator who has met with Mr Trump, and the GCHQ vigorously denied the charges in a rare public statement, saying the report was "utterly ridiculous and should be ignored".
British officials complained directly to White House officials after the episode, and Prime Minister Theresa May's office said it had been assured the White House would not repeat the allegations.
But Mr Trump himself offered no public apologies and suggested there was nothing wrong with the White House repeating what it had heard.